I have this problem as well. SSH negotiates everything it needs with the server, but times out when opening the final channel.
It only works when activating fasttrack for the connection in the firewall.
I haven't done extensive testing yet, but I can share a few observations:
- Somehow this only affects linux clients
- Ubuntu PC (ethernet) and Ubuntu Notebook (wifi): ssh client does not work
- Windows VM running on Linux (virtualbox on ubuntu, bridge interface): Putty does NOT work
- Windows PC: SSH works from Putty and WSL
- connecting to an ssh server over VPN works
- This started to happen suddenly after upgrading to 7.1beta2 (from stock 7.0beta6), but I still have it with 7.0beta8 (had to downgrade because of routing issues
- Fasttrack solves the problem
- My internet connection is flawless (thanks to the fantastic Chateau)
This is the end of the output of ssh -vvv:
debug2: channel 0: request shell confirm 1
debug3: send packet: type 98
debug2: channel_input_open_confirmation: channel 0: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
There is a serverfault thread
with exactly the same issue, just not mkrotik related. I tried about everything suggested there. The only fix/workaround in my case is fasttrack.